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Johnson KM, Lucani C, Brodribb TJ. In vivo monitoring of drought-induced embolism in Callitris rhomboidea trees reveals wide variation in branchlet vulnerability and high resistance to tissue death. THE NEW PHYTOLOGIST 2022; 233:207-218. [PMID: 34625973 DOI: 10.1111/nph.17786] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
Damage to the plant water transport system through xylem cavitation is known to be a driver of plant death in drought conditions. However, a lack of techniques to continuously monitor xylem embolism in whole plants in vivo has hampered our ability to investigate both how this damage propagates and the possible mechanistic link between xylem damage and tissue death. Using optical and fluorescence sensors, we monitored drought-induced xylem embolism accumulation and photosynthetic damage in vivo throughout the canopy of a drought-resistant conifer, Callitris rhomboidea, during drought treatments of c. 1 month duration. We show that drought-induced damage to the xylem can be monitored in vivo in whole trees during extended periods of water stress. Under these conditions, vulnerability of the xylem to cavitation varied widely among branchlets, with photosynthetic damage only recorded once > 90% of the xylem was cavitated. The variation in branchlet vulnerability has important implications for understanding how trees like C. rhomboidea survive drought, and the high resistance of branchlets to tissue damage points to runaway cavitation as a likely driver of tissue death in C. rhomboidea branch tips.
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Affiliation(s)
- Kate M Johnson
- Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, TAS, 7001, Australia
| | - Christopher Lucani
- Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, TAS, 7001, Australia
| | - Timothy J Brodribb
- Discipline of Biological Sciences, School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, TAS, 7001, Australia
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Hernandez JO, An JY, Combalicer MS, Chun JP, Oh SK, Park BB. Morpho-Anatomical Traits and Soluble Sugar Concentration Largely Explain the Responses of Three Deciduous Tree Species to Progressive Water Stress. FRONTIERS IN PLANT SCIENCE 2021; 12:738301. [PMID: 34950160 PMCID: PMC8688917 DOI: 10.3389/fpls.2021.738301] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 11/08/2021] [Indexed: 06/14/2023]
Abstract
A better understanding of plant drought responses is essential to improve plant water use efficiency, productivity, and resilience to ever-changing climatic conditions. Here, we investigated the growth, morpho-anatomical, physiological, and biochemical responses of Quercus acutissima Carruth., Quercus serrata Murray, and Betula schmidtii Regel to progressive water-stress. Seedlings were subjected to well-watered (WW) and water-stressed (WS) conditions while regularly monitoring the soil volumetric water content, stem diameter (SD), height, biomass, stomatal conductance (gs), intercellular CO2 concentration (Ci), and leaf relative water content (RWC). We also investigated the variation in stomatal pore (SP) area, specific leaf area (SLA), root xylem vessel diameter (VD), and total soluble sugar (TSS) concentration between treatments. After 2 months, WS significantly suppressed SD growth of Q. acutissima and B. schmidtii but had no impact on Q. serrata. Total biomass significantly declined at WS-treated seedlings in all species. WS resulted in a smaller SLA than WW in all species. The SP of WS-treated seedlings of Q. acutissima and B. schmidtii significantly decreased, whereas it increased significantly with time in Q. serrata. Larger vessels (i.e., >100 to ≤ 130) were more frequent at WS for Q. acutissima and B. schmidtii, whereas smaller vessels (i.e., >40 to ≤ 90) were more frequent at WS than at WW for Q. serrata after 8 weeks. Tylosis was more frequent at WS than WW for Q. serrata and B. schmidtii at eighth week. WS seedlings showed lower gs, Ci, and RWC compared with WW-treated ones in Q. acutissima and B. schmidtii. TSS concentration was also higher at WS-treated seedlings in two Quercus species. Overall, principal component analysis (PCA) showed that SLA and SP are associated with WS seedlings of Q. serrata and B. schmidtii and the tylosis frequency, TSS, and VD are associated with WS seedlings of Q. acutissima. Therefore, water-stressed plants from all species responded positively to water stress with increasing experimental duration and stress intensity, and that is largely explained by morpho-anatomical traits and soluble sugar concentration. The present study should enhance our understanding of drought-induced tree growth and short-term tree-seedling responses to drought.
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Affiliation(s)
- Jonathan O. Hernandez
- Department of Environment and Forest Resources, Chungnam National University, Daejeon, South Korea
- Department of Forest Biological Sciences, College of Forestry and Natural Resources, University of the Philippines Los Baños, Los Baños, Philippines
| | - Ji Young An
- Department of Environment and Forest Resources, Chungnam National University, Daejeon, South Korea
- Institute of Agricultural Science, College of Agriculture and Life Sciences, Chungnam National University, Daejeon, South Korea
| | - Marilyn S. Combalicer
- Department of Forest Biological Sciences, College of Forestry and Natural Resources, University of the Philippines Los Baños, Los Baños, Philippines
| | - Jong-Pil Chun
- Department of Horticulture, Chungnam National University, Daejeon, South Korea
| | - Sang-Keun Oh
- Department of Applied Biology, Chungnam National University, Daejeon, South Korea
| | - Byung Bae Park
- Department of Environment and Forest Resources, Chungnam National University, Daejeon, South Korea
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53
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Herrera JC, Savi T, Mattocks J, De Berardinis F, Scheffknecht S, Hietz P, Rosner S, Forneck A. Container volume affects drought experiments in grapevines: Insights on xylem anatomy and time of dehydration. PHYSIOLOGIA PLANTARUM 2021; 173:2181-2190. [PMID: 34549436 PMCID: PMC9293413 DOI: 10.1111/ppl.13567] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 09/08/2021] [Accepted: 09/21/2021] [Indexed: 05/15/2023]
Abstract
Plant stress experiments are commonly performed with plants grown in containers to better control environmental conditions. Nevertheless, the container can constrain plant growth and development, and this confounding effect is generally ignored, particularly in studies on woody species. Here, we evaluate the effect of the container volume in drought experiments using grapevine as a model plant. Grapevines grown in small (7 L, S) or large (20 L, L) containers were subjected to drought stress and rewatering treatments. We monitored plant stomatal conductance (gs ), midday stem water potential (Ψs ), and photosynthetic rate (AN ) throughout the experiment. The effect of the container volume on the stem and petiole xylem anatomy, as well as on the total leaf area (LA), was assessed before drought imposition. The results showed that LA did not differ between plants in L or S containers, but S vines exhibited a higher theoretical hydraulic conductance at the petiole level. Under drought L and S similarly reduced gs and AN , but plants in S containers reached lower Ψs than those in L. Nevertheless, upon rewatering droughted plants in S containers exhibited a faster stomata re-opening than those in L, probably as a consequence of the differences in the stress degree experienced and the biochemical adjustment at the leaf level. Therefore, a suitable experimental design should consider the container volume used in relation to the desired traits to be studied for unbiased results.
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Affiliation(s)
- Jose Carlos Herrera
- Institute of Viticulture and PomologyUniversity of Natural Resources and Life Science ViennaTullnAustria
| | - Tadeja Savi
- Institute of Viticulture and PomologyUniversity of Natural Resources and Life Science ViennaTullnAustria
- Institute of BotanyUniversity of Natural Resources and Life Science ViennaViennaAustria
| | - Joseph Mattocks
- Institute of Viticulture and PomologyUniversity of Natural Resources and Life Science ViennaTullnAustria
| | - Federica De Berardinis
- Institute of Viticulture and PomologyUniversity of Natural Resources and Life Science ViennaTullnAustria
| | - Susanne Scheffknecht
- Institute of BotanyUniversity of Natural Resources and Life Science ViennaViennaAustria
| | - Peter Hietz
- Institute of BotanyUniversity of Natural Resources and Life Science ViennaViennaAustria
| | - Sabine Rosner
- Institute of BotanyUniversity of Natural Resources and Life Science ViennaViennaAustria
| | - Astrid Forneck
- Institute of Viticulture and PomologyUniversity of Natural Resources and Life Science ViennaTullnAustria
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54
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Suissa JS, Friedman WE. From cells to stems: the effects of primary vascular construction on drought-induced embolism in fern rhizomes. THE NEW PHYTOLOGIST 2021; 232:2238-2253. [PMID: 34273190 DOI: 10.1111/nph.17629] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
While a considerable amount of data exists on the link between xylem construction and hydraulic function, few studies have focused on resistance to drought-induced embolism of primary vasculature in herbaceous plants. Ferns rely entirely on primary xylem and display a remarkable diversity of vascular construction in their rhizomes, making them an ideal group in which to examine hydraulic structure-function relationships. New optical methods allowed us to measure vulnerability to embolism in rhizomes, which are notoriously difficult to work with. We investigated five fern species based on their diverse xylem traits at the cellular, histological, and architectural levels. To link below- and above-ground hydraulics, we then measured leaf-stem vulnerability segmentation. Overall, rhizome vulnerability to embolism was correlated most strongly with cellular but not histological or architectural traits. Interestingly, at P6-12 , species with increased architectural dissection were actually more vulnerable to embolism, suggesting different hydraulic dynamics at low compared to high percent embolism. Importantly, leaves fully embolize before stems reach P88 , suggesting strong vulnerability segmentation. This is the first study to explore the functional implications of primary vascular construction in fern rhizomes and leaf-stem vulnerability segmentation. Strong segmentation suggests that leaves protect perennial rhizomes against severe drought stress and hydraulically induced mortality.
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Affiliation(s)
- Jacob S Suissa
- The Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
- The Arnold Arboretum of Harvard University, Boston, MA, 02131, USA
| | - William E Friedman
- The Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
- The Arnold Arboretum of Harvard University, Boston, MA, 02131, USA
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55
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Capelari ÉF, Dos Anjos L, Rodrigues NF, Sousa RMDJ, Silvera JAG, Margis R. Transcriptional profiling and physiological responses reveal new insights into drought tolerance in a semiarid adapted species, Anacardium occidentale. PLANT BIOLOGY (STUTTGART, GERMANY) 2021; 23:1074-1085. [PMID: 34418258 DOI: 10.1111/plb.13312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 05/05/2021] [Indexed: 06/13/2023]
Abstract
Water stress affects plant performance at various organisational levels, from morphological to molecular, with a drastic drop in crop yield. Integrative studies involving transcriptomics and physiological data in recognized tolerant species are appropriate strategies to identify and understand molecular and functional processes related to water deficit tolerance. The cashew tree (Anacardium occidentale) is a species naturally adapted to environments with low water availability associated with adverse conditions such as heat, high radiation and salinity. We used an integrative strategy, combining classical physiological measurements with high throughput RNA-seq to understand the main adaptive mechanisms of cashew to water deficit followed by recovery. Physiological analyses indicate that young cashew plants display typical isohydric behaviour. They first exhibit rapid stomatal closure, followed by CO2 assimilation, thus preserving the relative water content, membrane integrity and photosystem II activity. Differential expression was observed in 1733 genes from plant leaves exposed to water deficit stress for 26 days. Among them, 705 were upregulated and 1028 were downregulated. After rewatering, 1330 (76.7%) genes returned to their basal expression level. Transcriptional, combined with physiological data, reveal that cashew plants display high phenotypic plasticity and resilience to acute water deficit, and do not activate senescence pathways. A series of genes/pathways and processes involved with drought tolerance in cashew are evidenced, particularly in carbon metabolism, photosynthesis and chloroplast homeostasis.
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Affiliation(s)
- É F Capelari
- Programa de Pós Graduação em Genética e Biologia Molecular (PPGBM), Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - L Dos Anjos
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, CEP, Brazil
| | - N F Rodrigues
- Programa de Pós Graduação em Genética e Biologia Molecular (PPGBM), Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - R M de J Sousa
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, CEP, Brazil
| | - J A G Silvera
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, CEP, Brazil
| | - R Margis
- Programa de Pós Graduação em Genética e Biologia Molecular (PPGBM), Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Centro de Biotecnologia, Laboratório de Genomas e Populações de Plantas (LGPP), Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
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56
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Nadal-Sala D, Grote R, Birami B, Knüver T, Rehschuh R, Schwarz S, Ruehr NK. Leaf Shedding and Non-Stomatal Limitations of Photosynthesis Mitigate Hydraulic Conductance Losses in Scots Pine Saplings During Severe Drought Stress. FRONTIERS IN PLANT SCIENCE 2021; 12:715127. [PMID: 34539705 PMCID: PMC8448192 DOI: 10.3389/fpls.2021.715127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/08/2021] [Indexed: 06/01/2023]
Abstract
During drought, trees reduce water loss and hydraulic failure by closing their stomata, which also limits photosynthesis. Under severe drought stress, other acclimation mechanisms are trigged to further reduce transpiration to prevent irreversible conductance loss. Here, we investigate two of them: the reversible impacts on the photosynthetic apparatus, lumped as non-stomatal limitations (NSL) of photosynthesis, and the irreversible effect of premature leaf shedding. We integrate NSL and leaf shedding with a state-of-the-art tree hydraulic simulation model (SOX+) and parameterize them with example field measurements to demonstrate the stress-mitigating impact of these processes. We measured xylem vulnerability, transpiration, and leaf litter fall dynamics in Pinus sylvestris (L.) saplings grown for 54 days under severe dry-down. The observations showed that, once transpiration stopped, the rate of leaf shedding strongly increased until about 30% of leaf area was lost on average. We trained the SOX+ model with the observations and simulated changes in root-to-canopy conductance with and without including NSL and leaf shedding. Accounting for NSL improved model representation of transpiration, while model projections about root-to-canopy conductance loss were reduced by an overall 6%. Together, NSL and observed leaf shedding reduced projected losses in conductance by about 13%. In summary, the results highlight the importance of other than purely stomatal conductance-driven adjustments of drought resistance in Scots pine. Accounting for acclimation responses to drought, such as morphological (leaf shedding) and physiological (NSL) adjustments, has the potential to improve tree hydraulic simulation models, particularly when applied in predicting drought-induced tree mortality.
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Affiliation(s)
- Daniel Nadal-Sala
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
| | - Rüdiger Grote
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
| | - Benjamin Birami
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
- University of Bayreuth, Chair of Plant Ecology, Bayreuth, Germany
| | - Timo Knüver
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
- Department of Botany, University of Innsbruck, Innsbruck, Austria
| | - Romy Rehschuh
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
| | - Selina Schwarz
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
| | - Nadine K. Ruehr
- Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research - Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
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57
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Abate E, Nardini A, Petruzzellis F, Trifilò P. Too dry to survive: Leaf hydraulic failure in two Salvia species can be predicted on the basis of water content. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 166:215-224. [PMID: 34119871 DOI: 10.1016/j.plaphy.2021.05.046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/28/2021] [Indexed: 06/12/2023]
Abstract
Global warming is exposing plants to increased risks of drought-driven mortality. Recent advances suggest that hydraulic failure is a key process leading to plant death, and the identification of simple and reliable proxies of species-specific risk of irreversible hydraulic damage is urgently required. We assessed the predictive power of leaf water content and shrinkage for monitoring leaf hydraulic failure in two Mediterranean native species, Salvia ceratophylloides (Sc) and S. officinalis (So). The study species showed significant differences in relative water content (RWC) thresholds inducing loss of rehydration capacity, as well as leaf hydraulic conductance (KL) impairment. Sc turned out to be more resistant to drought than So. However, Sc and So showed different leaf saturated water content values, so that different RWC values actually corresponded to similar absolute leaf water content. Our findings suggest that absolute leaf water content and leaf water potential, but not RWC, are reliable parameters for predicting the risk of leaf hydraulic impairment of two Salvia species, and their potential risk of irreversible damage under severe drought. Moreover, the lack of any KL decline until the turgor loss point in Sc, coupled to consistent leaf shrinkage, rejects the hypothesis to use leaf shrinkage as a proxy to predict KL vulnerability, at least in species with high leaf capacitance. Robust linear correlations between KL decline and electrolyte leakage measurements suggested a role of membrane damage in driving leaf hydraulic collapse.
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Affiliation(s)
- Elisa Abate
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166, Messina, Italy
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127, Trieste, Italy
| | - Francesco Petruzzellis
- Dipartimento di Scienze AgroAlimentari, Ambientali e Animali, Università di Udine, Via delle Scienze 91, 33100, Udine, Italy
| | - Patrizia Trifilò
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, Università di Messina, Viale Ferdinando Stagno d'Alcontres 31, 98166, Messina, Italy.
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58
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Qin DW, Chen WJ, Zhong LX, Qin WM, Cao KF. Gas exchange and hydraulic function in seedlings of three basal angiosperm tree-species during water-withholding and re-watering. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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59
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Zhang FP, Zhang JL, Brodribb TJ, Hu H. Cavitation resistance of peduncle, petiole and stem is correlated with bordered pit dimensions in Magnolia grandiflora. PLANT DIVERSITY 2021; 43:324-330. [PMID: 34485775 PMCID: PMC8390921 DOI: 10.1016/j.pld.2020.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 11/04/2020] [Accepted: 11/05/2020] [Indexed: 05/05/2023]
Abstract
Variation in resistance of xylem to embolism among flowers, leaves, and stems strongly influences the survival and reproduction of plants. However, little is known about the vulnerability to xylem embolism under drought stress and their relationships to the anatomical traits of pits among reproductive and vegetative organs. In this study, we investigated the variation in xylem vulnerability to embolism in peduncles, petioles, and stems in a woody plant, Magnolia grandiflora. We analyzed the relationships between water potentials that induced 50% embolism (P50) in peduncles, petioles, and stems and the conduit pit traits hypothesized to influence cavitation resistance. We found that peduncles were more vulnerable to cavitation than petioles and stems, supporting the hypothesis of hydraulic vulnerability segmentation that leaves and stems are prioritized over flowers during drought stress. Moreover, P50 was significantly correlated with variation in the dimensions of inter-vessel pit apertures among peduncles, petioles and stems. These findings highlight that measuring xylem vulnerability to embolism in reproductive organs is essential for understanding the effect of drought on plant reproductive success and mortality under drought stress.
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Affiliation(s)
- Feng-Ping Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, Yunnan, China
- College of Traditional Chinese Medicine, Yunnan Key Laboratory of Dai and Yi Medicines, Yunnan University of Chinese Medicine, Kunming, 650500, Yunnan, China
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Yunnan Key Laboratory for Wild Plant Resources, Kunming 650201, Yunnan, China
| | - Jiao-Lin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, Yunnan, China
- Corresponding author.
| | - Timothy J. Brodribb
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia
| | - Hong Hu
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, Yunnan Key Laboratory for Wild Plant Resources, Kunming 650201, Yunnan, China
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60
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Walker RP, Bonghi C, Varotto S, Battistelli A, Burbidge CA, Castellarin SD, Chen ZH, Darriet P, Moscatello S, Rienth M, Sweetman C, Famiani F. Sucrose Metabolism and Transport in Grapevines, with Emphasis on Berries and Leaves, and Insights Gained from a Cross-Species Comparison. Int J Mol Sci 2021; 22:7794. [PMID: 34360556 PMCID: PMC8345980 DOI: 10.3390/ijms22157794] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/09/2021] [Accepted: 07/13/2021] [Indexed: 01/14/2023] Open
Abstract
In grapevines, as in other plants, sucrose and its constituents glucose and fructose are fundamentally important and carry out a multitude of roles. The aims of this review are three-fold. First, to provide a summary of the metabolism and transport of sucrose in grapevines, together with new insights and interpretations. Second, to stress the importance of considering the compartmentation of metabolism. Third, to outline the key role of acid invertase in osmoregulation associated with sucrose metabolism and transport in plants.
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Affiliation(s)
| | - Claudio Bonghi
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova Agripolis, 35020 Legnaro, Italy;
| | - Serena Varotto
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova Agripolis, 35020 Legnaro, Italy;
| | - Alberto Battistelli
- Istituto di Ricerca sugli Ecosistemi Terrestri, Consiglio Nazionale delle Ricerche, 05010 Porano, Italy; (A.B.); (S.M.)
| | | | - Simone D. Castellarin
- Wine Research Centre, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC V6T 0Z4, Canada;
| | - Zhi-Hui Chen
- College of Life Science, University of Dundee, Dundee DD1 5EH, UK;
| | - Philippe Darriet
- Cenologie, Institut des Sciences de la Vigne et du Vin (ISVV), 33140 Villenave d’Ornon, France;
| | - Stefano Moscatello
- Istituto di Ricerca sugli Ecosistemi Terrestri, Consiglio Nazionale delle Ricerche, 05010 Porano, Italy; (A.B.); (S.M.)
| | - Markus Rienth
- Changins College for Viticulture and Oenology, University of Sciences and Art Western Switzerland, 1260 Nyon, Switzerland;
| | - Crystal Sweetman
- College of Science & Engineering, Flinders University, GPO Box 5100, Adelaide, SA 5001, Australia;
| | - Franco Famiani
- Dipartimento di Scienze Agrarie, Alimentari e Ambientali, Università degli Studi di Perugia, 06121 Perugia, Italy
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61
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A microscopic study on scattering in tissue section of Alternanthera philoxeroides under polarized light. J Biosci 2021. [DOI: 10.1007/s12038-021-00174-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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62
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A minimally disruptive method for measuring water potential in planta using hydrogel nanoreporters. Proc Natl Acad Sci U S A 2021; 118:2008276118. [PMID: 34074748 PMCID: PMC8201978 DOI: 10.1073/pnas.2008276118] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Gaps in our ability to document local water relations in leaves compromise our ability to build complete models of leaf and plant function and our understanding of ecophysiological phenomena, such as response and adaptation to drought. Macroscopically, leaf water potential has been shown to impact vegetative growth and yield, susceptibility to disease, and, in extreme drought, plant viability, making it a promising candidate trait to improve water-use efficiency in plants. In this paper, we present a nanoscale sensor (AquaDust) that provides minimally disruptive measurements of water potential in leaves of intact plants at high spatial and temporal resolution. This creates opportunities for improving our understanding of the mechanisms coupling variations in water potential to biological and physical processes. Leaf water potential is a critical indicator of plant water status, integrating soil moisture status, plant physiology, and environmental conditions. There are few tools for measuring plant water status (water potential) in situ, presenting a critical barrier for developing appropriate phenotyping (measurement) methods for crop development and modeling efforts aimed at understanding water transport in plants. Here, we present the development of an in situ, minimally disruptive hydrogel nanoreporter (AquaDust) for measuring leaf water potential. The gel matrix responds to changes in water potential in its local environment by swelling; the distance between covalently linked dyes changes with the reconfiguration of the polymer, leading to changes in the emission spectrum via Förster Resonance Energy Transfer (FRET). Upon infiltration into leaves, the nanoparticles localize within the apoplastic space in the mesophyll; they do not enter the cytoplasm or the xylem. We characterize the physical basis for AquaDust’s response and demonstrate its function in intact maize (Zea mays L.) leaves as a reporter of leaf water potential. We use AquaDust to measure gradients of water potential along intact, actively transpiring leaves as a function of water status; the localized nature of the reporters allows us to define a hydraulic model that distinguishes resistances inside and outside the xylem. We also present field measurements with AquaDust through a full diurnal cycle to confirm the robustness of the technique and of our model. We conclude that AquaDust offers potential opportunities for high-throughput field measurements and spatially resolved studies of water relations within plant tissues.
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Bortolami G, Farolfi E, Badel E, Burlett R, Cochard H, Ferrer N, King A, Lamarque LJ, Lecomte P, Marchesseau-Marchal M, Pouzoulet J, Torres-Ruiz JM, Trueba S, Delzon S, Gambetta GA, Delmas CEL. Seasonal and long-term consequences of esca grapevine disease on stem xylem integrity. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:3914-3928. [PMID: 33718947 DOI: 10.1093/jxb/erab117] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 03/11/2021] [Indexed: 05/26/2023]
Abstract
Hydraulic failure has been extensively studied during drought-induced plant dieback, but its role in plant-pathogen interactions is under debate. During esca, a grapevine (Vitis vinifera) disease, symptomatic leaves are prone to irreversible hydraulic dysfunctions but little is known about the hydraulic integrity of perennial organs over the short- and long-term. We investigated the effects of esca on stem hydraulic integrity in naturally infected plants within a single season and across season(s). We coupled direct (ks) and indirect (kth) hydraulic conductivity measurements, and tylose and vascular pathogen detection with in vivo X-ray microtomography visualizations. Xylem occlusions (tyloses) and subsequent loss of stem hydraulic conductivity (ks) occurred in all shoots with severe symptoms (apoplexy) and in more than 60% of shoots with moderate symptoms (tiger-stripe), with no tyloses in asymptomatic shoots. In vivo stem observations demonstrated that tyloses occurred only when leaf symptoms appeared, and resulted in more than 50% loss of hydraulic conductance in 40% of symptomatic stems, unrelated to symptom age. The impact of esca on xylem integrity was only seasonal, with no long-term impact of disease history. Our study demonstrated how and to what extent a vascular disease such as esca, affecting xylem integrity, could amplify plant mortality through hydraulic failure.
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Affiliation(s)
| | - Elena Farolfi
- INRAE, BSA, ISVV, SAVE, 33882 Villenave d'Ornon, France
| | - Eric Badel
- Université Clermont-Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
| | - Regis Burlett
- Univ. Bordeaux, INRAE, BIOGECO, 33615 Pessac, France
| | - Herve Cochard
- Université Clermont-Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
| | | | - Andrew King
- Synchrotron SOLEIL, L'Orme des Merisiers, Gif-sur-Yvette, 91192, France
| | - Laurent J Lamarque
- Univ. Bordeaux, INRAE, BIOGECO, 33615 Pessac, France
- Département des Sciences de l'Environnement, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, G9A 5H7, Canada
| | | | | | - Jerome Pouzoulet
- EGFV, Bordeaux-Sciences Agro, INRAE, Université de Bordeaux, ISVV, 210 chemin de Leysotte, 33882 Villenave d'Ornon, France
| | - Jose M Torres-Ruiz
- Université Clermont-Auvergne, INRAE, PIAF, 63000 Clermont-Ferrand, France
| | - Santiago Trueba
- Univ. Bordeaux, INRAE, BIOGECO, 33615 Pessac, France
- School of Forestry and Environmental Studies, Yale University, New Haven, CT 06511, USA
| | | | - Gregory A Gambetta
- EGFV, Bordeaux-Sciences Agro, INRAE, Université de Bordeaux, ISVV, 210 chemin de Leysotte, 33882 Villenave d'Ornon, France
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64
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Guan X, Pereira L, McAdam SAM, Cao KF, Jansen S. No gas source, no problem: Proximity to pre-existing embolism and segmentation affect embolism spreading in angiosperm xylem by gas diffusion. PLANT, CELL & ENVIRONMENT 2021; 44:1329-1345. [PMID: 33529382 DOI: 10.1111/pce.14016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 01/16/2021] [Accepted: 01/17/2021] [Indexed: 05/12/2023]
Abstract
Embolism spreading in dehydrating angiosperm xylem is driven by gas movement between embolized and sap-filled conduits. Here we examine how the proximity to pre-existing embolism and hydraulic segmentation affect embolism propagation. Based on the optical method, we compare xylem embolism resistance between detached leaves and leaves attached to branches, and between intact leaves and leaves with cut minor veins, for six species. Embolism resistance of detached leaves was significantly lower than that of leaves attached to stems, except for two species, with all vessels ending in their petioles. Cutting of minor veins showed limited embolism spreading in minor veins near the cuts prior to major veins. Moreover, despite strong agreement in the overall embolism resistance of detached leaves between the optical and pneumatic method, minor differences were observed during early stages of embolism formation. We conclude that embolism resistance may represent a relative trait due to an open-xylem artefact, with embolism spreading possibly affected by the proximity and connectivity to pre-existing embolism as a gas source, while hydraulic segmentation prevents such artefact. Since embolism formation may not rely on a certain pressure difference threshold between functional and embolized conduits, we speculate that embolism is facilitated by pressure-driven gas diffusion across pit membranes.
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Affiliation(s)
- Xinyi Guan
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
| | - Luciano Pereira
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
- Laboratory of Plant Physiology "Coaracy M. Franco", Center R&D in Ecophysiology and Biophysics, Agronomic Institute (IAC), Campinas, Brazil
- Laboratory of Crop Physiology, Department of Plant Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Scott A M McAdam
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, USA
| | - Kun-Fang Cao
- Plant Ecophysiology and Evolution Group, State Key Laboratory for Conservation and Utilisation of Subtropical Agro-Bioresources, Guangxi University, Nanning, China
- Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, China
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
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65
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Alonso-Forn D, Peguero-Pina JJ, Ferrio JP, Mencuccini M, Mendoza-Herrer Ó, Sancho-Knapik D, Gil-Pelegrín E. Contrasting functional strategies following severe drought in two Mediterranean oaks with different leaf habit: Quercus faginea and Quercus ilex subsp. rotundifolia. TREE PHYSIOLOGY 2021; 41:371-387. [PMID: 33079165 DOI: 10.1093/treephys/tpaa135] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/04/2020] [Accepted: 10/08/2020] [Indexed: 06/11/2023]
Abstract
Nowadays, evergreen sclerophyllous and winter-deciduous malacophyllous oaks with different paleogeographical origins coexist under Mediterranean-type climates, such as the mixed forests of the evergreen Quercus ilex subsp. rotundifolia Lam. and the winter-deciduous Quercus faginea Lam. Both Mediterranean oaks constitute two examples of contrasting leaf habit, so it could be expected that they would have different functional strategies to cope with summer drought. In this study, we analysed photosynthetic, photochemical and hydraulic traits of different organs for Q. faginea and Q. ilex subsp. rotundifolia under well-watered conditions and subjected to very severe drought. The coordinated response between photosynthetic and hydraulic traits explained the higher photosynthetic capacity of Q. faginea under well-watered conditions, which compensated its shorter leaf life span at the expense of higher water consumption. The progressive imposition of water stress evidenced that both types of Mediterranean oaks displayed different functional strategies to cope with water limitations. Specifically, the decrease in mesophyll conductance associated with edaphic drought seems to be the main factor explaining the differences found in the dynamics of net CO2 assimilation throughout the drought period. The sharp decline in photosynthetic traits of Q. faginea was coupled with a strong decrease in shoot hydraulic conductance in response to drought. This fact probably avoided extensive xylem embolism in the stems (i.e., 'vulnerability segmentation'), which enabled new leaf development after drought period in Q. faginea. By contrast, leaves of Q. ilex subsp. rotundifolia showed effective photoprotective mechanisms and high resistance to drought-induced cavitation, which would be related with the longer leaf life span of the evergreen Mediterranean oaks. The co-occurrence of both types of Mediterranean oaks could be related to edaphic conditions that ensure the maintenance of soil water potential above critical values for Q. faginea, which can be severely affected by soil degradation and climate change.
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Affiliation(s)
- David Alonso-Forn
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda Montañana 930, 50059, Zaragoza, Spain
| | - José Javier Peguero-Pina
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda Montañana 930, 50059, Zaragoza, Spain
- Instituto Agroalimentario de Aragón -IA2-(CITA-Universidad de Zaragoza), Zaragoza, Spain
| | - Juan Pedro Ferrio
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda Montañana 930, 50059, Zaragoza, Spain
- Aragon Agency for Research and Development (ARAID), E-50018 Zaragoza, Spain
| | - Maurizio Mencuccini
- Centre de Recerca Ecològica i Aplicacions Forestals (CREAF), Campus UAB, Cerdanyola del Vallés, 08193 Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, 08010, Spain
| | - Óscar Mendoza-Herrer
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda Montañana 930, 50059, Zaragoza, Spain
| | - Domingo Sancho-Knapik
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda Montañana 930, 50059, Zaragoza, Spain
- Instituto Agroalimentario de Aragón -IA2-(CITA-Universidad de Zaragoza), Zaragoza, Spain
| | - Eustaquio Gil-Pelegrín
- Unidad de Recursos Forestales, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Avda Montañana 930, 50059, Zaragoza, Spain
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66
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Abstract
Since 1893, when the word "photosynthesis" was first coined by Charles Reid Barnes and Conway MacMillan, our understanding of the elements and regulation of this complex process is far from being entirely understood. We aim to review the most relevant advances in photosynthesis research from the last few years and to provide a perspective on the forthcoming research in this field. Recent discoveries related to light sensing, harvesting, and dissipation; kinetics of CO2 fixation; components and regulators of CO2 diffusion through stomata and mesophyll; and genetic engineering for improving photosynthetic and production capacities of crops are addressed.
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Affiliation(s)
- Alicia V Perera-Castro
- Department of Biology, Universitat de les Illes Balears, INAGEA, Palma de Mallorca, Spain
| | - Jaume Flexas
- Department of Biology, Universitat de les Illes Balears, INAGEA, Palma de Mallorca, Spain
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67
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Bartlett MK, Sinclair G. Temperature and evaporative demand drive variation in stomatal and hydraulic traits across grape cultivars. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:1995-2009. [PMID: 33300576 DOI: 10.1093/jxb/eraa577] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
Selection for crop cultivars has largely focused on reproductive traits, while the impacts of global change on crop productivity are expected to depend strongly on the vegetative physiology traits that drive plant resource use and stress tolerance. We evaluated relationships between physiology traits and growing season climate across wine grape cultivars to characterize trait variation across European growing regions. We compiled values from the literature for seven water use and drought tolerance traits and growing season climate. Cultivars with a lower maximum stomatal conductance were associated with regions with a higher mean temperature and mean and maximum vapor pressure deficit (r2=0.39-0.65, P<0.05, n=14-29). Cultivars with greater stem embolism resistance and more anisohydric stomatal behavior (i.e. a more negative water potential threshold for 50% stomatal closure) were associated with cooler regions (r2=0.48-0.72, P<0.03, n=10-29). Overall, cultivars grown in warmer, drier regions exhibited traits that would reduce transpiration and conserve soil water longer into the growing season, but potentially increase stomatal and temperature limitations on photosynthesis under future, hotter conditions.
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Affiliation(s)
- Megan K Bartlett
- Department of Viticulture & Enology, University of California, Davis, CA, USA
| | - Gabriela Sinclair
- Department of Viticulture & Enology, University of California, Davis, CA, USA
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68
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Sorek Y, Greenstein S, Netzer Y, Shtein I, Jansen S, Hochberg U. An increase in xylem embolism resistance of grapevine leaves during the growing season is coordinated with stomatal regulation, turgor loss point and intervessel pit membranes. THE NEW PHYTOLOGIST 2021; 229:1955-1969. [PMID: 33098088 DOI: 10.1111/nph.17025] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/02/2020] [Indexed: 05/27/2023]
Abstract
Although xylem embolism resistance is traditionally considered as static, we hypothesized that in grapevine (Vitis vinifera) leaf xylem becomes more embolism-resistant over the growing season. We evaluated xylem architecture, turgor loss point (ΨTLP ) and water potentials leading to 25% of maximal stomatal conductance (gs25 ) or 50% embolism in the leaf xylem (P50 ) in three irrigation treatments and at three time points during the growing season, while separating the effects of leaf age and time of season. Hydraulic traits acclimated over the growing season in a coordinated manner. Without irrigation, ΨTLP , gs25 , and P50 decreased between late May and late August by 0.95, 0.77 and 0.71 MPa, respectively. A seasonal shift in P50 occurred even in mature leaves, while irrigation had only a mild effect (< 0.2 MPa) on P50 . Vessel size and pit membrane thickness were also seasonally dynamic, providing a plausible explanation for the shift in P50 . Our findings provide clear evidence that grapevines can modify their hydraulic traits along a growing season to allow lower xylem water potential, without compromising gas exchange, leaf turgor or xylem integrity. Seasonal changes should be considered when modeling ecosystem vulnerability to drought or comparing datasets acquired at different phenological stages.
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Affiliation(s)
- Yonatan Sorek
- Institute of Soil, Water and Environmental Science, Volcani Center, Agricultural Research Organization, PO Box 6, Bet-Dagan, 50250, Israel
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel
| | - Smadar Greenstein
- Institute of Soil, Water and Environmental Science, Volcani Center, Agricultural Research Organization, PO Box 6, Bet-Dagan, 50250, Israel
| | - Yishai Netzer
- Department of Chemical engineering, Ariel University, Ariel, 40700, Israel
- Agriculture and Oenology Department, Eastern R&D Center, Ariel, 40700, Israel
| | - Ilana Shtein
- Agriculture and Oenology Department, Eastern R&D Center, Ariel, 40700, Israel
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Albert-Einstein-Allee 11, Ulm, D-89081, Germany
| | - Uri Hochberg
- Institute of Soil, Water and Environmental Science, Volcani Center, Agricultural Research Organization, PO Box 6, Bet-Dagan, 50250, Israel
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69
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Trenti M, Lorenzi S, Bianchedi PL, Grossi D, Failla O, Grando MS, Emanuelli F. Candidate genes and SNPs associated with stomatal conductance under drought stress in Vitis. BMC PLANT BIOLOGY 2021; 21:7. [PMID: 33407127 PMCID: PMC7789618 DOI: 10.1186/s12870-020-02739-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 11/16/2020] [Indexed: 05/03/2023]
Abstract
BACKGROUND Understanding the complexity of the vine plant's response to water deficit represents a major challenge for sustainable winegrowing. Regulation of water use requires a coordinated action between scions and rootstocks on which cultivars are generally grafted to cope with phylloxera infestations. In this regard, a genome-wide association study (GWAS) approach was applied on an 'ad hoc' association mapping panel including different Vitis species, in order to dissect the genetic basis of transpiration-related traits and to identify genomic regions of grape rootstocks associated with drought tolerance mechanisms. The panel was genotyped with the GrapeReSeq Illumina 20 K SNP array and SSR markers, and infrared thermography was applied to estimate stomatal conductance values during progressive water deficit. RESULTS In the association panel the level of genetic diversity was substantially lower for SNPs loci (0.32) than for SSR (0.87). GWAS detected 24 significant marker-trait associations along the various stages of drought-stress experiment and 13 candidate genes with a feasible role in drought response were identified. Gene expression analysis proved that three of these genes (VIT_13s0019g03040, VIT_17s0000g08960, VIT_18s0001g15390) were actually induced by drought stress. Genetic variation of VIT_17s0000g08960 coding for a raffinose synthase was further investigated by resequencing the gene of 85 individuals since a SNP located in the region (chr17_10,497,222_C_T) was significantly associated with stomatal conductance. CONCLUSIONS Our results represent a step forward towards the dissection of genetic basis that modulate the response to water deprivation in grape rootstocks. The knowledge derived from this study may be useful to exploit genotypic and phenotypic diversity in practical applications and to assist further investigations.
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Affiliation(s)
- Massimiliano Trenti
- Research and Innovation Centre, Fondazione Edmund Mach, via E. Mach 1, 38010 San Michele all’Adige, Italy
| | - Silvia Lorenzi
- Research and Innovation Centre, Fondazione Edmund Mach, via E. Mach 1, 38010 San Michele all’Adige, Italy
| | - Pier Luigi Bianchedi
- Technology Transfer Centre, Fondazione Edmund Mach, via E. Mach 1, 38010 San Michele all’Adige, Italy
| | - Daniele Grossi
- Department of Agricultural and Environmental Sciences, University of Milano, via Celoria 2, 20133 Milan, Italy
| | - Osvaldo Failla
- Department of Agricultural and Environmental Sciences, University of Milano, via Celoria 2, 20133 Milan, Italy
| | - Maria Stella Grando
- Research and Innovation Centre, Fondazione Edmund Mach, via E. Mach 1, 38010 San Michele all’Adige, Italy
- Center Agriculture Food Environment (C3A), University of Trento, via E. Mach 1, 38010 San Michele all’Adige, Italy
| | - Francesco Emanuelli
- Research and Innovation Centre, Fondazione Edmund Mach, via E. Mach 1, 38010 San Michele all’Adige, Italy
- Department of Agricultural and Environmental Sciences, University of Milano, via Celoria 2, 20133 Milan, Italy
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70
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Albuquerque C, Scoffoni C, Brodersen CR, Buckley TN, Sack L, McElrone AJ. Coordinated decline of leaf hydraulic and stomatal conductances under drought is not linked to leaf xylem embolism for different grapevine cultivars. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:7286-7300. [PMID: 33306796 DOI: 10.1093/jxb/eraa392] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 10/27/2020] [Indexed: 06/12/2023]
Abstract
Drought decreases water transport capacity of leaves and limits gas exchange, which involves reduced leaf leaf hydraulic conductance (Kleaf) in both the xylem and outside-xylem pathways. Some literature suggests that grapevines are hyper-susceptible to drought-induced xylem embolism. We combined Kleaf and gas exchange measurements, micro-computed tomography of intact leaves, and spatially explicit modeling of the outside-xylem pathways to evaluate the role of vein embolism and Kleaf in the responses of two different grapevine cultivars to drought. Cabernet Sauvignon and Chardonnay exhibited similar vulnerabilities of Kleaf and gs to dehydration, decreasing substantially prior to leaf xylem embolism. Kleaf and gs decreased by 80% for both cultivars by Ψ leaf approximately -0.7 MPa and -1.2 MPa, respectively, while leaf xylem embolism initiated around Ψ leaf = -1.25 MPa in the midribs and little to no embolism was detected in minor veins even under severe dehydration for both cultivars. Modeling results indicated that reduced membrane permeability associated with a Casparian-like band in the leaf vein bundle sheath would explain declines in Kleaf of both cultivars. We conclude that during moderate water stress, changes in the outside-xylem pathways, rather than xylem embolism, are responsible for reduced Kleaf and gs. Understanding this mechanism could help to ensure adequate carbon capture and crop performance under drought.
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Affiliation(s)
- Caetano Albuquerque
- Department of Viticulture and Enology, University of California, Davis, 595 Hilgard Lane, Davis, CA, USA
| | - Christine Scoffoni
- Department of Biological Sciences, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA, USA
| | - Craig R Brodersen
- School of the Environment, Yale University, 195 Prospect Street, New Haven, CT, USA
| | - Thomas N Buckley
- Department of Plant Sciences, University of California, Davis, One Shields Avenue, Davis, CA, USA
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA, USA
| | - Andrew J McElrone
- Department of Viticulture and Enology, University of California, Davis, 595 Hilgard Lane, Davis, CA, USA
- USDA-Agricultural Research Service, Davis, CA, USA
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71
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Marusig D, Tombesi S. Abscisic Acid Mediates Drought and Salt Stress Responses in Vitis vinifera-A Review. Int J Mol Sci 2020; 21:E8648. [PMID: 33212767 PMCID: PMC7698233 DOI: 10.3390/ijms21228648] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 11/09/2020] [Accepted: 11/15/2020] [Indexed: 12/18/2022] Open
Abstract
The foreseen increase in evaporative demand and reduction in rainfall occurrence are expected to stress the abiotic constrains of drought and salt concentration in soil. The intensification of abiotic stresses coupled with the progressive depletion in water pools is a major concern especially in viticulture, as most vineyards rely on water provided by rainfall. Because its economical relevance and its use as a model species for the study of abiotic stress effect on perennial plants, a significant amount of literature has focused on Vitis vinifera, assessing the physiological mechanisms occurring under stress. Despite the complexity of the stress-resistance strategy of grapevine, the ensemble of phenomena involved seems to be regulated by the key hormone abscisic acid (ABA). This review aims at summarizing our knowledge on the role of ABA in mediating mechanisms whereby grapevine copes with abiotic stresses and to highlight aspects that deserve more attention in future research.
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Affiliation(s)
| | - Sergio Tombesi
- Dipartimento di Scienze delle Produzioni Vegetali Sostenibili, Università Cattolica del Sacro Cuore, 29122 Piacenza, Italy;
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72
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Levionnois S, Ziegler C, Jansen S, Calvet E, Coste S, Stahl C, Salmon C, Delzon S, Guichard C, Heuret P. Vulnerability and hydraulic segmentations at the stem-leaf transition: coordination across Neotropical trees. THE NEW PHYTOLOGIST 2020; 228:512-524. [PMID: 32496575 DOI: 10.1111/nph.16723] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 05/18/2020] [Indexed: 05/23/2023]
Abstract
Hydraulic segmentation at the stem-leaf transition predicts higher hydraulic resistance in leaves than in stems. Vulnerability segmentation, however, predicts lower embolism resistance in leaves. Both mechanisms should theoretically favour runaway embolism in leaves to preserve expensive organs such as stems, and should be tested for any potential coordination. We investigated the theoretical leaf-specific conductivity based on an anatomical approach to quantify the degree of hydraulic segmentation across 21 tropical rainforest tree species. Xylem resistance to embolism in stems (flow-centrifugation technique) and leaves (optical visualization method) was quantified to assess vulnerability segmentation. We found a pervasive hydraulic segmentation across species, but with a strong variability in the degree of segmentation. Despite a clear continuum in the degree of vulnerability segmentation, eight species showed a positive vulnerability segmentation (leaves less resistant to embolism than stems), whereas the remaining species studied exhibited a negative or no vulnerability segmentation. The degree of vulnerability segmentation was positively related to the degree of hydraulic segmentation, such that segmented species promote both mechanisms to hydraulically decouple leaf xylem from stem xylem. To what extent hydraulic and vulnerability segmentation determine drought resistance requires further integration of the leaf-stem transition at the whole-plant level, including both xylem and outer xylem tissue.
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Affiliation(s)
- Sébastien Levionnois
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
- AMAP , Univ Montpellier , CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
| | - Camille Ziegler
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
- UMR SILVA, INRAE , Université de Lorraine, Nancy, 54000, France
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, D-89081, Germany
| | - Emma Calvet
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Sabrina Coste
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Clément Stahl
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Camille Salmon
- AMAP , Univ Montpellier , CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
| | - Sylvain Delzon
- Univ. Bordeaux , INRAE, BIOGECO, Pessac, F-33615, France
| | - Charlotte Guichard
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
| | - Patrick Heuret
- UMR EcoFoG, AgroParisTech, CIRAD, CNRS, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
- AMAP , Univ Montpellier , CIRAD, CNRS, INRAE, IRD, Montpellier, 34000, France
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73
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Abscisic Acid Biosynthesis and Signaling in Plants: Key Targets to Improve Water Use Efficiency and Drought Tolerance. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10186322] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The observation of a much-improved fitness of wild-type plants over abscisic acid (ABA)-deficient mutants during drought has led researchers from all over to world to perform experiments aiming at a better understanding of how this hormone modulates the physiology of plants under water-limited conditions. More recently, several promising approaches manipulating ABA biosynthesis and signaling have been explored to improve water use efficiency and confer drought tolerance to major crop species. Here, we review recent progress made in the last decade on (i) ABA biosynthesis, (ii) the roles of ABA on plant-water relations and on primary and secondary metabolisms during drought, and (iii) the regulation of ABA levels and perception to improve water use efficiency and drought tolerance in crop species.
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Gambetta GA, Herrera JC, Dayer S, Feng Q, Hochberg U, Castellarin SD. The physiology of drought stress in grapevine: towards an integrative definition of drought tolerance. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:4658-4676. [PMID: 32433735 PMCID: PMC7410189 DOI: 10.1093/jxb/eraa245] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 05/14/2020] [Indexed: 05/17/2023]
Abstract
Water availability is arguably the most important environmental factor limiting crop growth and productivity. Erratic precipitation patterns and increased temperatures resulting from climate change will likely make drought events more frequent in many regions, increasing the demand on freshwater resources and creating major challenges for agriculture. Addressing these challenges through increased irrigation is not always a sustainable solution so there is a growing need to identify and/or breed drought-tolerant crop varieties in order to maintain sustainability in the context of climate change. Grapevine (Vitis vinifera), a major fruit crop of economic importance, has emerged as a model perennial fruit crop for the study of drought tolerance. This review synthesizes the most recent results on grapevine drought responses, the impact of water deficit on fruit yield and composition, and the identification of drought-tolerant varieties. Given the existing gaps in our knowledge of the mechanisms underlying grapevine drought responses, we aim to answer the following question: how can we move towards a more integrative definition of grapevine drought tolerance?
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Affiliation(s)
- Gregory A Gambetta
- EGFV, Bordeaux-Sciences Agro, INRA, Université de Bordeaux, ISVV, chemin de Leysotte, Villenave d’Ornon, France
- Correspondence: or
| | - Jose Carlos Herrera
- Institute of Viticulture and Pomology, Department of Crop Sciences, University of Natural Resources and Life Sciences Vienna (BOKU), Tulln, Austria
| | - Silvina Dayer
- EGFV, Bordeaux-Sciences Agro, INRA, Université de Bordeaux, ISVV, chemin de Leysotte, Villenave d’Ornon, France
| | - Quishuo Feng
- Wine Research Centre, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, BC, Canada
| | - Uri Hochberg
- ARO Volcani Center, Institute of Soil, Water and Environmental Sciences, Rishon Lezion, Israel
| | - Simone D Castellarin
- Wine Research Centre, Faculty of Land and Food Systems, The University of British Columbia, Vancouver, BC, Canada
- Correspondence: or
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75
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Cardoso AA, Billon LM, Fanton Borges A, Fernández-de-Uña L, Gersony JT, Güney A, Johnson KM, Lemaire C, Mrad A, Wagner Y, Petit G. New developments in understanding plant water transport under drought stress. THE NEW PHYTOLOGIST 2020; 227:1025-1027. [PMID: 32662102 DOI: 10.1111/nph.16663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Affiliation(s)
- Amanda A Cardoso
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
| | - Lise-Marie Billon
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
| | - Ana Fanton Borges
- Yale School of Forestry and Environmental Studies, Yale University, 195 Prospect Street, New Haven, CT, 06511, USA
| | | | - Jess T Gersony
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Aylin Güney
- Institute of Botany, University of Hohenheim, Garbenstr 30, D-70599, Stuttgart, Germany
- Department of Biology, Faculty of Science, Akdeniz University, 07058, Antalya, Turkey
| | - Kate M Johnson
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia
| | - Cédric Lemaire
- Université Clermont Auvergne, INRAE, PIAF, 63000, Clermont-Ferrand, France
| | - Assaad Mrad
- Nicholas School of the Environment, Duke University, Durham, NC, 27708, USA
| | - Yael Wagner
- Department of Plant & Environmental Sciences, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Giai Petit
- Department TeSAF, Università degli Studi di Padova, Viale dell'Università 16, 35020, Legnaro, Italy
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76
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Brunetti C, Savi T, Nardini A, Loreto F, Gori A, Centritto M. Changes in abscisic acid content during and after drought are related to carbohydrate mobilization and hydraulic recovery in poplar stems. TREE PHYSIOLOGY 2020; 40:1043-1057. [PMID: 32186735 DOI: 10.1093/treephys/tpaa032] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 02/26/2020] [Accepted: 03/13/2020] [Indexed: 06/10/2023]
Abstract
Drought compromises plant's ability to replace transpired water vapor with water absorbed from the soil, leading to extensive xylem dysfunction and causing plant desiccation and death. Short-term plant responses to drought rely on stomatal closure, and on the plant's ability to recover hydraulic functioning after drought relief. We hypothesize a key role for abscisic acid (ABA) not only in the control of stomatal aperture, but also in hydraulic recovery. Young plants of Populus nigra L. were used to investigate possible relationships among ABA, non-structural carbohydrates (NSC) and xylem hydraulic function under drought and after re-watering. In Populus nigra L. plants subjected to drought, water transport efficiency and hydraulic recovery after re-watering were monitored by measuring the percentage loss of hydraulic conductivity (PLC) and stem specific hydraulic conductivity (Kstem). In the same plants ABA and NSC were quantified in wood and bark. Drought severely reduced stomatal conductance (gL) and markedly increased the PLC. Leaf and stem water potential, and stem hydraulic efficiency fully recovered within 24 h after re-watering, but gL values remained low. After re-watering, we found significant correlations between changes in ABA content and hexoses concentration both in wood and bark. Our findings suggest a role for ABA in the regulation of stem carbohydrate metabolism and starch mobilization upon drought relief, possibly promoting the restoration of xylem transport capacity.
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Affiliation(s)
- Cecilia Brunetti
- National Research Council of Italy, Institute for Sustainable Plant Protection, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Florence), Italy
| | - Tadeja Savi
- University of Natural Resources and Life Sciences, Institute of Botany, Department of Integrative Biology and Biodiversity Research, BOKU, Gregor-Mendel-Straße 33, 1190, Vienna, Austria Austria
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy
| | - Francesco Loreto
- National Research Council of Italy, Department of Biology, Agriculture and Food Sciences, Piazzale Aldo Moro 7, 00185 Roma, Italy
| | - Antonella Gori
- Department of Agri-Food Production and Environmental Sciences, University of Florence, Viale delle Idee 30, 50019 Sesto Fiorentino (Florence), Italy
| | - Mauro Centritto
- National Research Council of Italy, Institute for Sustainable Plant Protection, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Florence), Italy
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77
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Dayer S, Herrera JC, Dai Z, Burlett R, Lamarque LJ, Delzon S, Bortolami G, Cochard H, Gambetta GA. The sequence and thresholds of leaf hydraulic traits underlying grapevine varietal differences in drought tolerance. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:4333-4344. [PMID: 32279077 PMCID: PMC7337184 DOI: 10.1093/jxb/eraa186] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 04/10/2020] [Indexed: 05/20/2023]
Abstract
Adapting agriculture to climate change is driving the need for the selection and breeding of drought-tolerant crops. The aim of this study was to identify key drought tolerance traits and determine the sequence of their water potential thresholds across three grapevine cultivars with contrasting water use behaviors, Grenache, Syrah, and Semillon. We quantified differences in water use between cultivars and combined this with the determination of other leaf-level traits (e.g. leaf turgor loss point, π TLP), leaf vulnerability to embolism (P50), and the hydraulic safety margin (HSM P50). Semillon exhibited the highest maximum transpiration (Emax), and lowest sensitivity of canopy stomatal conductance (Gc) to vapor pressure deficit (VPD), followed by Syrah and Grenache. Increasing Emax was correlated with more negative water potential at which stomata close (Pgs90), π TLP, and P50, suggesting that increasing water use is associated with hydraulic traits allowing gas exchange under more negative water potentials. Nevertheless, all the cultivars closed their stomata prior to leaf embolism formation. Modeling simulations demonstrated that despite a narrower HSM, Grenache takes longer to reach thresholds of hydraulic failure due to its conservative water use. This study demonstrates that the relationships between leaf hydraulic traits are complex and interactive, stressing the importance of integrating multiple traits in characterizing drought tolerance.
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Affiliation(s)
- Silvina Dayer
- EGFV, Bordeaux-Sciences Agro, INRA, Université de Bordeaux, ISVV, Villenave d’Ornon, France
- Correspondence:
| | - José Carlos Herrera
- Institute of Viticulture and Pomology, University of Natural Resources and Life Sciences (BOKU), Tulln, Austria
| | - Zhanwu Dai
- Beijing Key Laboratory of Grape Science and Enology and Key Laboratory of Plant Resources, Institute of Botany, the Chinese Academy of Sciences, Beijing, China
| | - Régis Burlett
- Biodiversité Gènes et Communautés, Institut National de la Recherche Agronomique (INRA), Université Bordeaux, Cestas, France
| | - Laurent J Lamarque
- Biodiversité Gènes et Communautés, Institut National de la Recherche Agronomique (INRA), Université Bordeaux, Cestas, France
| | - Sylvain Delzon
- Biodiversité Gènes et Communautés, Institut National de la Recherche Agronomique (INRA), Université Bordeaux, Cestas, France
| | | | - Hervé Cochard
- Université Clermont-Auvergne, INRA, PIAF, Clermont-Ferrand, France
| | - Gregory A Gambetta
- EGFV, Bordeaux-Sciences Agro, INRA, Université de Bordeaux, ISVV, Villenave d’Ornon, France
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78
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Bourbia I, Carins-Murphy MR, Gracie A, Brodribb TJ. Xylem cavitation isolates leaky flowers during water stress in pyrethrum. THE NEW PHYTOLOGIST 2020; 227:146-155. [PMID: 32130731 DOI: 10.1111/nph.16516] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 02/20/2020] [Indexed: 06/10/2023]
Abstract
Flowers underpin plant evolution, genetic legacy and global food supply. They are exposed to similar evaporative conditions as leaves, yet floral physiology is a product of different selective forces. We used Tanacetum cinerariifolium, a perennial daisy, to examine the response of flowers to whole-plant water stress, determining if flowers constitute a liability during drought, and how this species has adapted to minimize risk associated with reproduction. We determined the relative transpiration cost of flowers and leaves and confirmed that flowers in this species are xylem-hydrated. The relative water stress tolerance of leaves and flowers then was compared using xylem vulnerability measurements linked with observed tissue damage during an acute drought treatment. Flowers were a major source of water loss during drought but the xylem supplying them was much more vulnerable to cavitation than leaves. This xylem vulnerability segmentation was confirmed by observations that most flowers died whereas leaves were minimally affected during drought. Early cavitation and hydraulic isolation of flowers during drought benefits the plant by slowing the dehydration of perennial vegetative organs and delaying systemic xylem damage. Our results highlight the need to understand flower xylem vulnerability as a means of predicting plant reproductive failure under future drought.
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Affiliation(s)
- Ibrahim Bourbia
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tas., 7001, Australia
| | - Madeline R Carins-Murphy
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tas., 7001, Australia
| | - Alistair Gracie
- Tasmania Institute of Agriculture, University of Tasmania, Private Bag 54, Hobart, Tas., 7001, Australia
| | - Timothy J Brodribb
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tas., 7001, Australia
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79
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Meixner M, Tomasella M, Foerst P, Windt CW. A small-scale MRI scanner and complementary imaging method to visualize and quantify xylem embolism formation. THE NEW PHYTOLOGIST 2020; 226:1517-1529. [PMID: 31958150 DOI: 10.1111/nph.16442] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 01/12/2020] [Indexed: 05/13/2023]
Abstract
Magnetic resonance imaging (MRI) is a useful tool to image xylem embolism formation in plants. MRI scanners configured to accept intact plants are rare and expensive. Here, we investigate if affordable small-scale, custom-built low-field MRI scanners would suffice for the purpose. A small-scale, C-shaped permanent magnet was paired with open, plane parallel imaging gradients. The setup was small enough to fit between leaves or branches and offered open access for plant stems of arbitrary length. To counter the two main drawbacks of the system, low signal to noise and reduced magnetic field homogeneity, a multi-spin echo (MSE) pulse sequence was implemented, allowing efficient signal acquisition and quantitative imaging of water content and T2 signal relaxation. The system was tested visualizing embolism formation in Fagus sylvatica during bench dehydration. High-quality images of water content and T2 were readily obtained, which could be utilized to detect the cavitation of vessels smaller than could be spatially resolved. A multiplication of both map types yielded images in which filled xylem appeared with even greater contrast. T2 imaging with small-scale MRI devices allows straightforward visualization of the spatial and temporal dynamics of embolism formation and the derivation of vulnerability curves.
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Affiliation(s)
- Marco Meixner
- Process Systems Engineering, Technical University of Munich, Gregor-Mendel-Straße 4, 85354, Freising, Germany
- IBG-2: Plant Sciences Institute, Forschungszentrum Jülich, Leo-Brandt-Straße 1, 52428, Jülich, Germany
| | - Martina Tomasella
- Chair for Ecophysiology of Plants, Technical University Munich, Hans-Carl-von-Carlowitz-Platz 2, 85354, Freising, Germany
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127, Trieste, Italy
| | - Petra Foerst
- Process Systems Engineering, Technical University of Munich, Gregor-Mendel-Straße 4, 85354, Freising, Germany
| | - Carel W Windt
- IBG-2: Plant Sciences Institute, Forschungszentrum Jülich, Leo-Brandt-Straße 1, 52428, Jülich, Germany
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80
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Schuldt B, Buras A, Arend M, Vitasse Y, Beierkuhnlein C, Damm A, Gharun M, Grams TE, Hauck M, Hajek P, Hartmann H, Hiltbrunner E, Hoch G, Holloway-Phillips M, Körner C, Larysch E, Lübbe T, Nelson DB, Rammig A, Rigling A, Rose L, Ruehr NK, Schumann K, Weiser F, Werner C, Wohlgemuth T, Zang CS, Kahmen A. A first assessment of the impact of the extreme 2018 summer drought on Central European forests. Basic Appl Ecol 2020. [DOI: 10.1016/j.baae.2020.04.003] [Citation(s) in RCA: 172] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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81
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Pratt RB, Castro V, Fickle JC, Madsen A, Jacobsen AL. Factors controlling drought resistance in grapevine (Vitis vinifera, chardonnay): application of a new microCT method to assess functional embolism resistance. AMERICAN JOURNAL OF BOTANY 2020; 107:618-627. [PMID: 32232845 DOI: 10.1002/ajb2.1450] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 01/15/2020] [Indexed: 06/10/2023]
Abstract
PREMISE Quantifying resistance to embolism in woody plants is important for understanding their drought response. Methods to accurately quantify resistance to embolism continue to be debated. METHODS We used a new microCT-based approach that quantifies embolized conduits and also analyzes conductive conduits by using an x-ray-dense, iodine-rich tracer that moves though the vascular system and can easily be observed in microCT images. Many previous microCT studies assumed that all conduits were initially conductive, which may not be the case if there are developing or occluded conduits. We compared microCT results to a standard benchtop dehydration method and a centrifuge method. During dehydration, we measured gas exchange and quantified water potential at mortality. RESULTS Our microCT curves agreed with previously published microCT curves from the same greenhouse-grown cultivar. We found a significant difference in embolism estimates if we assumed that all water-filled conduits were functional rather than only those containing tracer. Embolism estimates from microCT differed from both the benchtop and centrifuge methods. The benchtop and centrifuge methods did not differ from one another. CONCLUSIONS The new microCT method presented here is valuable in sampling species that may contain nonconductive conduits. Disagreement between microCT and two other methods was likely due to differences in the ways they quantify embolism. MicroCT assess the theoretical effect of embolism, whereas benchtop and centrifuge methods directly measure hydraulic conductivity. The theoretical approach does not fully account for the resistances of flow through a complex 3D vascular network.
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Affiliation(s)
- R Brandon Pratt
- Department of Biology, California State University-Bakersfield, Bakersfield, CA, 93311, USA
| | - Viridiana Castro
- Department of Biology, California State University-Bakersfield, Bakersfield, CA, 93311, USA
| | - Jaycie C Fickle
- Department of Biology, California State University-Bakersfield, Bakersfield, CA, 93311, USA
| | - Angela Madsen
- Department of Biology, California State University-Bakersfield, Bakersfield, CA, 93311, USA
| | - Anna L Jacobsen
- Department of Biology, California State University-Bakersfield, Bakersfield, CA, 93311, USA
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82
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Lamarque LJ, Delzon S, Toups H, Gravel AI, Corso D, Badel E, Burlett R, Charrier G, Cochard H, Jansen S, King A, Torres-Ruiz JM, Pouzoulet J, Cramer GR, Thompson AJ, Gambetta GA. Over-accumulation of abscisic acid in transgenic tomato plants increases the risk of hydraulic failure. PLANT, CELL & ENVIRONMENT 2020; 43:548-562. [PMID: 31850535 DOI: 10.1111/pce.13703] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 11/11/2019] [Accepted: 12/03/2019] [Indexed: 05/27/2023]
Abstract
Climate change threatens food security, and plant science researchers have investigated methods of sustaining crop yield under drought. One approach has been to overproduce abscisic acid (ABA) to enhance water use efficiency. However, the concomitant effects of ABA overproduction on plant vascular system functioning are critical as it influences vulnerability to xylem hydraulic failure. We investigated these effects by comparing physiological and hydraulic responses to water deficit between a tomato (Solanum lycopersicum) wild type control (WT) and a transgenic line overproducing ABA (sp12). Under well-watered conditions, the sp12 line displayed similar growth rate and greater water use efficiency by operating at lower maximum stomatal conductance. X-ray microtomography revealed that sp12 was significantly more vulnerable to xylem embolism, resulting in a reduced hydraulic safety margin. We also observed a significant ontogenic effect on vulnerability to xylem embolism for both WT and sp12. This study demonstrates that the greater water use efficiency in the tomato ABA overproducing line is associated with higher vulnerability of the vascular system to embolism and a higher risk of hydraulic failure. Integrating hydraulic traits into breeding programmes represents a critical step for effectively managing a crop's ability to maintain hydraulic conductivity and productivity under water deficit.
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Affiliation(s)
- Laurent J Lamarque
- BIOGECO, INRA, Univ. Bordeaux, Pessac, France
- EGFV, Bordeaux-Sciences Agro, INRA, Univ. Bordeaux, ISVV, Villenave d'Ornon, France
| | | | - Haley Toups
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Nevada
| | | | | | - Eric Badel
- INRA, PIAF, Université Clermont-Auvergne, Clermont-Ferrand, France
| | | | | | - Hervé Cochard
- INRA, PIAF, Université Clermont-Auvergne, Clermont-Ferrand, France
| | - Steven Jansen
- Institute of Systematic Botany and Ecology, Ulm University, Ulm, Germany
| | - Andrew King
- Synchrotron SOLEIL, Gif-sur-Yvette Cedex, France
| | | | - Jérôme Pouzoulet
- EGFV, Bordeaux-Sciences Agro, INRA, Univ. Bordeaux, ISVV, Villenave d'Ornon, France
| | - Grant R Cramer
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, Nevada
| | - Andrew J Thompson
- Cranfield Soil an Agrifood Institute, Cranfield University, Bedfordshire, UK
| | - Gregory A Gambetta
- EGFV, Bordeaux-Sciences Agro, INRA, Univ. Bordeaux, ISVV, Villenave d'Ornon, France
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83
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Petruzzellis F, Tomasella M, Miotto A, Natale S, Trifilò P, Nardini A. A Leaf Selfie: Using a Smartphone to Quantify Leaf Vulnerability to Hydraulic Dysfunction. PLANTS (BASEL, SWITZERLAND) 2020; 9:E234. [PMID: 32054113 PMCID: PMC7076359 DOI: 10.3390/plants9020234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/21/2020] [Accepted: 02/05/2020] [Indexed: 05/28/2023]
Abstract
Accurate predictions of species distribution under current and future climate conditions require modeling efforts based on clear mechanistic relationships between climate variables and plant physiological functions. Vulnerability of leaves to xylem embolism is a key mechanistic trait that might be included in these modeling efforts. Here, we propose a simple set-up to measure leaf vulnerability to embolism on the basis of the optical method using a smartphone, a light source, and a notebook. Our data show that this proposed set-up can adequately quantify the vulnerability to xylem embolism of leaf major veins in Populus nigra and Ostrya carpinifolia, producing values consistent with those obtained in temperate tree species with other methods, allowing virtually any laboratory to quantify species-specific drought tolerance on the basis of a sound mechanistic trait.
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Affiliation(s)
- Francesco Petruzzellis
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy; (F.P.); (M.T.); (A.M.); (S.N.)
| | - Martina Tomasella
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy; (F.P.); (M.T.); (A.M.); (S.N.)
| | - Andrea Miotto
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy; (F.P.); (M.T.); (A.M.); (S.N.)
| | - Sara Natale
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy; (F.P.); (M.T.); (A.M.); (S.N.)
| | - Patrizia Trifilò
- Dipartimento di Scienze chimiche, biologiche, farmaceutiche e ambientali, Università di Messina, Viale Ferdinando Stagno d’Alcontres 31, 98166 Messina, Italy;
| | - Andrea Nardini
- Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, 34127 Trieste, Italy; (F.P.); (M.T.); (A.M.); (S.N.)
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84
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Smith‐Martin CM, Skelton RP, Johnson KM, Lucani C, Brodribb TJ. Lack of vulnerability segmentation among woody species in a diverse dry sclerophyll woodland community. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13519] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Chris M. Smith‐Martin
- Department of Ecology, Evolution and Evolutionary Biology Columbia University New York NY USA
| | - Robert Paul Skelton
- South African Environmental Observation NetworkKirstenbosch Botanical Gardens Cape Town South Africa
| | - Kate M. Johnson
- School of Biological Sciences University of Tasmania Hobart TAS Australia
| | - Christopher Lucani
- School of Biological Sciences University of Tasmania Hobart TAS Australia
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85
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Li X, Smith R, Choat B, Tissue DT. Drought resistance of cotton (Gossypium hirsutum) is promoted by early stomatal closure and leaf shedding. FUNCTIONAL PLANT BIOLOGY : FPB 2020; 47:91-98. [PMID: 31825787 DOI: 10.1071/fp19093] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 09/06/2019] [Indexed: 05/11/2023]
Abstract
Water relations have been well documented in tree species, but relatively little is known about the hydraulic characteristics of crops. Here, we report on the hydraulic strategy of cotton (Gossypium hirsutum L.). Leaf gas exchange and in vivo embolism formation were monitored simultaneously on plants that were dried down in situ under controlled environment conditions, and xylem vulnerability to embolism of leaves, stems and roots was measured using intact plants. Water potential inducing 50% embolised vessels (P50) in leaves was significantly higher (less negative) than P50 of stems and roots, suggesting that leaves were the most vulnerable organ to embolism. Furthermore, the water potential generating stomatal closure (Pgs) was higher than required to generate embolism formation, and complete stomatal closure always preceded the onset of embolism with declining soil water content. Although protracted drought resulted in massive leaf shedding, stem embolism remained minimal even after ~90% leaf area was lost. Overall, cotton maintained hydraulic integrity during long-term drought stress through early stomatal closure and leaf shedding, thus exhibiting a drought avoidance strategy. Given that water potentials triggering xylem embolism are uncommon under field conditions, cotton is unlikely to experience hydraulic dysfunction except under extreme climates. Results of this study provide physiological evidence for drought resistance in cotton with regard to hydraulics, and may provide guidance in developing irrigation schedules during periods of water shortage.
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Affiliation(s)
- Ximeng Li
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Renee Smith
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia; and Corresponding author.
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86
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Creek D, Lamarque LJ, Torres-Ruiz JM, Parise C, Burlett R, Tissue DT, Delzon S. Xylem embolism in leaves does not occur with open stomata: evidence from direct observations using the optical visualization technique. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:1151-1159. [PMID: 31641746 DOI: 10.1093/jxb/erz474] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 10/11/2019] [Indexed: 06/10/2023]
Abstract
Drought represents a major abiotic constraint to plant growth and survival. On the one hand, plants keep stomata open for efficient carbon assimilation while, on the other hand, they close them to prevent permanent hydraulic impairment from xylem embolism. The order of occurrence of these two processes (stomatal closure and the onset of leaf embolism) during plant dehydration has remained controversial, largely due to methodological limitations. However, the newly developed optical visualization method now allows concurrent monitoring of stomatal behaviour and leaf embolism formation in intact plants. We used this new approach directly by dehydrating intact saplings of three contrasting tree species and indirectly by conducting a literature survey across a greater range of plant taxa. Our results indicate that increasing water stress generates the onset of leaf embolism consistently after stomatal closure, and that the lag time between these processes (i.e. the safety margin) rises with increasing embolism resistance. This suggests that during water stress, embolism-mediated declines in leaf hydraulic conductivity are unlikely to act as a signal for stomatal down-regulation. Instead, these species converge towards a strategy of closing stomata early to prevent water loss and delay catastrophic xylem dysfunction.
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Affiliation(s)
- Danielle Creek
- Université Clermont-Auvergne, INRA, PIAF, Clermont-Ferrand, France
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | | | | | | | - Regis Burlett
- BIOGECO, INRA, Université de Bordeaux, Pessac, France
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
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87
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Holloway-Phillips M. Variation in Xylem Resistance to Cavitation Explains Why Some Leaves Within a Canopy Are More Likely to Die under Water Stress. PLANT PHYSIOLOGY 2020; 182:450-452. [PMID: 31908323 PMCID: PMC6945845 DOI: 10.1104/pp.19.01394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
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88
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Rodriguez-Dominguez CM, Brodribb TJ. Declining root water transport drives stomatal closure in olive under moderate water stress. THE NEW PHYTOLOGIST 2020; 225:126-134. [PMID: 31498457 DOI: 10.1111/nph.16177] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 09/01/2019] [Indexed: 05/24/2023]
Abstract
Efficient water transport from soil to leaves sustains stomatal opening and steady-state photosynthesis. The aboveground portion of this pathway is well-described, yet the roots and their connection with the soil are still poorly understood due to technical limitations. Here we used a novel rehydration technique to investigate changes in the hydraulic pathway between roots and soil and within the plant body as individual olive plants were subjected to a range of water stresses. Whole root hydraulic resistance (including the radial pathway from xylem to the soil-root interface) constituted 81% of the whole-plant resistance in unstressed plants, increasing to > 95% under a moderate level of water stress. The decline in this whole root hydraulic conductance occurred in parallel with stomatal closure and contributed significantly to the reduction in canopy conductance according to a hydraulic model. Our results demonstrate that losses in root hydraulic conductance, mainly due to a disconnection from the soil during moderate water stress in olive plants, are profound and sufficient to induce stomatal closure before cavitation occurs. Future studies will determine whether this core regulatory role of root hydraulics exists more generally among diverse plant species.
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Affiliation(s)
- Celia M Rodriguez-Dominguez
- Irrigation and Crop Ecophysiology Group, Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS, CSIC), Avenida Reina Mercedes, 10, 41012, Sevilla, Spain
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS, 7001, Australia
| | - Timothy J Brodribb
- School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, TAS, 7001, Australia
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89
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Cardoso AA, Batz TA, McAdam SAM. Xylem Embolism Resistance Determines Leaf Mortality during Drought in Persea americana. PLANT PHYSIOLOGY 2020; 182:547-554. [PMID: 31624082 PMCID: PMC6945834 DOI: 10.1104/pp.19.00585] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 10/10/2019] [Indexed: 05/08/2023]
Abstract
The driver of leaf mortality during drought stress is a critical unknown. We used the commercially important tree Persea americana, in which there is a large variation in the degree of drought-induced leaf death across the canopy, to test whether embolism formation in the xylem during drought drives this leaf mortality. A large range in the number of embolized vessels in the petioles of leaves was observed across the canopy of plants that had experienced drought. Despite considerable variation between leaves, the amount of embolized vessels in the xylem of the petiole strongly correlated with area of drought-induced tissue death in individual leaves. Consistent with this finding was a large interleaf variability in xylem resistance to embolism, with a 1.45 MPa variation in the water potential at which 50% of the xylem in the leaf midrib embolized across leaves. Our results implicate xylem embolism as a driver of leaf mortality during drought. Moreover, we propose that heterogeneity in drought-induced leaf mortality across a canopy is caused by high interleaf variability in xylem resistance to embolism, which may act as a buffer against complete canopy death during prolonged drought in P. americana.
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Affiliation(s)
- Amanda A Cardoso
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
| | - Timothy A Batz
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
| | - Scott A M McAdam
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
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90
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Bouda M, Windt CW, McElrone AJ, Brodersen CR. In vivo pressure gradient heterogeneity increases flow contribution of small diameter vessels in grapevine. Nat Commun 2019; 10:5645. [PMID: 31822680 DOI: 10.17605/osf.io/ey2tj] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 11/19/2019] [Indexed: 05/26/2023] Open
Abstract
Leaves lose approximately 400 H2O molecules for every 1 CO2 gained during photosynthesis. Most long-distance water transport in plants, or xylem sap flow, serves to replace this water to prevent desiccation. Theory predicts that the largest vessels contribute disproportionately to overall sap flow because flow in pipe-like systems scales with the fourth power of radius. Here, we confront these theoretical flow predictions for a vessel network reconstructed from X-ray μCT imagery with in vivo flow MRI observations from the same sample of a first-year grapevine stem. Theoretical flow rate predictions based on vessel diameters are not supported. The heterogeneity of the vessel network gives rise to transverse pressure gradients that redirect flow from wide to narrow vessels, reducing the contribution of wide vessels to sap flow by 15% of the total. Our results call for an update of the current working model of the xylem to account for its heterogeneity.
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Affiliation(s)
- Martin Bouda
- School of Forestry & Environmental Studies, Yale University, 195 Prospect St., New Haven, CT, 06511, USA.
- Institute of Botany of the Czech Academy of Sciences, Zámek 1, 25243, Průhonice, Czech Republic.
| | - Carel W Windt
- IBG-2: Plant Sciences, Forschungszentrum Jülich, Leo Brandt Straße 1, 52428, Jülich, Germany
| | - Andrew J McElrone
- Department of Viticulture & Enology, University of California, 595 Hilgard Ln, Davis, CA, 95616, USA
- USDA-ARS, Crops Pathology and Genetics Research Unit, Davis, CA, USA
| | - Craig R Brodersen
- School of Forestry & Environmental Studies, Yale University, 195 Prospect St., New Haven, CT, 06511, USA
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91
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Bouda M, Windt CW, McElrone AJ, Brodersen CR. In vivo pressure gradient heterogeneity increases flow contribution of small diameter vessels in grapevine. Nat Commun 2019; 10:5645. [PMID: 31822680 PMCID: PMC6904565 DOI: 10.1038/s41467-019-13673-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 11/19/2019] [Indexed: 11/16/2022] Open
Abstract
Leaves lose approximately 400 H2O molecules for every 1 CO2 gained during photosynthesis. Most long-distance water transport in plants, or xylem sap flow, serves to replace this water to prevent desiccation. Theory predicts that the largest vessels contribute disproportionately to overall sap flow because flow in pipe-like systems scales with the fourth power of radius. Here, we confront these theoretical flow predictions for a vessel network reconstructed from X-ray μCT imagery with in vivo flow MRI observations from the same sample of a first-year grapevine stem. Theoretical flow rate predictions based on vessel diameters are not supported. The heterogeneity of the vessel network gives rise to transverse pressure gradients that redirect flow from wide to narrow vessels, reducing the contribution of wide vessels to sap flow by 15% of the total. Our results call for an update of the current working model of the xylem to account for its heterogeneity. Plants require long-distance water transport to avoid desiccation. Here, via μCT and MRI of grapevine stem, Bouda et al. show evidence of pressure gradient heterogeneity and flow redirection from wide to narrow vessels that suggests narrow vessels contribute more to xylem sap flow than previously appreciated.
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Affiliation(s)
- Martin Bouda
- School of Forestry & Environmental Studies, Yale University, 195 Prospect St., New Haven, CT, 06511, USA. .,Institute of Botany of the Czech Academy of Sciences, Zámek 1, 25243, Průhonice, Czech Republic.
| | - Carel W Windt
- IBG-2: Plant Sciences, Forschungszentrum Jülich, Leo Brandt Straße 1, 52428, Jülich, Germany
| | - Andrew J McElrone
- Department of Viticulture & Enology, University of California, 595 Hilgard Ln, Davis, CA, 95616, USA.,USDA-ARS, Crops Pathology and Genetics Research Unit, Davis, CA, USA
| | - Craig R Brodersen
- School of Forestry & Environmental Studies, Yale University, 195 Prospect St., New Haven, CT, 06511, USA
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92
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Blackman CJ, Li X, Choat B, Rymer PD, De Kauwe MG, Duursma RA, Tissue DT, Medlyn BE. Desiccation time during drought is highly predictable across species of Eucalyptus from contrasting climates. THE NEW PHYTOLOGIST 2019; 224:632-643. [PMID: 31264226 DOI: 10.1111/nph.16042] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 06/27/2019] [Indexed: 05/19/2023]
Abstract
Catastrophic failure of the water transport pathway in trees is a principal mechanism of mortality during extreme drought. To be able to predict the probability of mortality at an individual and landscape scale we need knowledge of the time for plants to reach critical levels of hydraulic failure. We grew plants of eight species of Eucalyptus originating from contrasting climates before allowing a subset to dehydrate. We tested whether a trait-based model of time to plant desiccation tcrit , from stomatal closure gs90 to a critical level of hydraulic dysfunction Ψcrit is consistent with observed dry-down times. Plant desiccation time varied among species, ranging from 96.2 to 332 h at a vapour-pressure deficit of 1 kPa, and was highly predictable using the tcrit model in conjunction with a leaf shedding function. Plant desiccation time was longest in species with high cavitation resistance, strong vulnerability segmentation, wide stomatal-hydraulic safety, and a high ratio of total plant water content to leaf area. Knowledge of tcrit in combination with water-use traits that influence stomatal closure could significantly increase our ability to predict the timing of drought-induced mortality at tree and forest scales.
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Affiliation(s)
- Chris J Blackman
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
- Université Clermont-Auvergne, INRA, PIAF, 63000, Clermont-Ferrand, France
| | - Ximeng Li
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Brendan Choat
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Paul D Rymer
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Martin G De Kauwe
- ARC Centre of Excellence for Extreme Climates, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Remko A Duursma
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - David T Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Belinda E Medlyn
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
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93
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Drought-Induced Mortality Is Related to Hydraulic Vulnerability Segmentation of Tree Species in a Savanna Ecosystem. FORESTS 2019. [DOI: 10.3390/f10080697] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vulnerability segmentation (VS) has been widely suggested to protect stems and trunks from hydraulic failure during drought events. In many ecosystems, some species have been shown to be non-segmented (NS species). However, it is unclear whether drought-induced mortality is related to VS. To understand this, we surveyed the mortality and recruitment rate and measured the hydraulic traits of leaves and stems as well as the photosynthesis of six tree species over five years (2012–2017) in a savanna ecosystem in Southwest China. Our results showed that the NS species exhibited a higher mortality rate than the co-occurring VS species. Across species, the mortality rate was not correlated with xylem tension at 50% loss of stem hydraulic conductivity (P50stem), but was rather significantly correlated with leaf water potential at 50% loss of leaf hydraulic conductance (P50leaf) and the difference in water potential at 50% loss of hydraulic conductance between the leaves and terminal stems (P50leaf-stem). The NS species had higher Huber values and maximum net photosynthetic rates based on leaf area, which compensated for a higher mortality rate and promoted rapid regeneration under the conditions of dry–wet cycles. To our knowledge, this study is the first to identify the difference in drought-induced mortality between NS species and VS species. Our results emphasize the importance of VS in maintaining hydraulic safety in VS species. Furthermore, the high mortality rate and fast regeneration in NS species may be another hydraulic strategy in regions where severe seasonal droughts are frequent.
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94
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Skelton RP, Anderegg LDL, Papper P, Reich E, Dawson TE, Kling M, Thompson SE, Diaz J, Ackerly DD. No local adaptation in leaf or stem xylem vulnerability to embolism, but consistent vulnerability segmentation in a North American oak. THE NEW PHYTOLOGIST 2019; 223:1296-1306. [PMID: 31059125 DOI: 10.1111/nph.15886] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 04/21/2019] [Indexed: 05/23/2023]
Abstract
Vulnerability to embolism varies between con-generic species distributed along aridity gradients, yet little is known about intraspecific variation and its drivers. Even less is known about intraspecific variation in tissues other than stems, despite results suggesting that roots, stems and leaves can differ in vulnerability. We hypothesized that intraspecific variation in vulnerability in leaves and stems is adaptive and driven by aridity. We quantified leaf and stem vulnerability of Quercus douglasii using the optical technique. To assess contributions of genetic variation and phenotypic plasticity to within-species variation, we quantified the vulnerability of individuals growing in a common garden, but originating from populations along an aridity gradient, as well as individuals from the same wild populations. Intraspecific variation in water potential at which 50% of total embolism in a tissue is observed (P50 ) was explained mostly by differences between individuals (>66% of total variance) and tissues (16%). There was little between-population variation in leaf/stem P50 in the garden, which was not related to site of origin aridity. Unexpectedly, we observed a positive relationship between wild individual stem P50 and aridity. Although there is no local adaptation and only minor phenotypic plasticity in leaf/stem vulnerability in Q. douglasii, high levels of potentially heritable variation within populations or strong environmental selection could contribute to adaptive responses under future climate change.
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Affiliation(s)
- Robert P Skelton
- Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA
| | - Leander D L Anderegg
- Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA
- Carnegie Science, Stanford University, Stanford, CA, 94305, USA
| | - Prahlad Papper
- Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA
| | - Emma Reich
- Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA
| | - Todd E Dawson
- Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, 94720, USA
| | - Matthew Kling
- Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA
| | - Sally E Thompson
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720, USA
- School of Civil, Environmental and Mining Engineering, University of Western Australia, Perth, 6907, Australia
| | - Jessica Diaz
- Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA
| | - David D Ackerly
- Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, 94720, USA
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95
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Trueba S, Pan R, Scoffoni C, John GP, Davis SD, Sack L. Thresholds for leaf damage due to dehydration: declines of hydraulic function, stomatal conductance and cellular integrity precede those for photochemistry. THE NEW PHYTOLOGIST 2019; 223:134-149. [PMID: 30843202 DOI: 10.1111/nph.15779] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Accepted: 02/18/2019] [Indexed: 05/04/2023]
Abstract
Given increasing water deficits across numerous ecosystems world-wide, it is urgent to understand the sequence of failure of leaf function during dehydration. We assessed dehydration-induced losses of rehydration capacity and maximum quantum yield of the photosystem II (Fv /Fm ) in the leaves of 10 diverse angiosperm species, and tested when these occurred relative to turgor loss, declines of stomatal conductance gs , and hydraulic conductance Kleaf , including xylem and outside xylem pathways for the same study plants. We resolved the sequences of relative water content and leaf water potential Ψleaf thresholds of functional impairment. On average, losses of leaf rehydration capacity occurred at dehydration beyond 50% declines of gs , Kleaf and turgor loss point. Losses of Fv /Fm occurred after much stronger dehydration and were not recovered with leaf rehydration. Across species, tissue dehydration thresholds were intercorrelated, suggesting trait co-selection. Thresholds for each type of functional decline were much less variable across species in terms of relative water content than Ψleaf . The stomatal and leaf hydraulic systems show early functional declines before cell integrity is lost. Substantial damage to the photochemical apparatus occurs at extreme dehydration, after complete stomatal closure, and seems to be irreversible.
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Affiliation(s)
- Santiago Trueba
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA, 90095, USA
| | - Ruihua Pan
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA, 90095, USA
- School of Ecology and Environment, Inner Mongolia University, 235 University West Road, Hohhot, Inner Mongolia, 010021, China
| | - Christine Scoffoni
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA, 90095, USA
- Department of Biological Sciences, California State University Los Angeles, 5151 State University Drive, Los Angeles, CA, 90032, USA
| | - Grace P John
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA, 90095, USA
- Department of Integrative Biology, University of Texas at Austin, 2415 Speedway, Austin, TX, 78712, USA
| | - Stephen D Davis
- Natural Science Division, Pepperdine University, Malibu, CA, 90263-4321, USA
| | - Lawren Sack
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA, 90095, USA
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96
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Hochberg U, Ponomarenko A, Zhang YJ, Rockwell FE, Holbrook NM. Visualizing Embolism Propagation in Gas-Injected Leaves. PLANT PHYSIOLOGY 2019; 180:874-881. [PMID: 30842264 PMCID: PMC6548249 DOI: 10.1104/pp.18.01284] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 02/20/2019] [Indexed: 05/15/2023]
Abstract
Because the xylem in leaves is thought to be at the greatest risk of cavitation, reliable and efficient methods to characterize leaf xylem vulnerability are of interest. We report a method to generate leaf xylem vulnerability curves (VCs) by gas injection. Using optical light transmission, we visualized embolism propagation in grapevine (Vitis vinifera) and red oak (Quercus rubra) leaves injected with positive gas pressure. This resulted in a rapid, stepwise reduction of transmitted light, identical to that observed during leaf dehydration, confirming that the optical method detects gas bubbles and provides insights into the air-seeding hypothesis. In red oak, xylem VCs generated using gas injection were similar to those generated using bench dehydration, but indicated 50% loss of conductivity at lower tension (∼0.4 MPa) in grapevine. In determining VC, this method eliminates the need to ascertain xylem tension, thus avoiding potential errors in water potential estimations. It is also much faster (1 h per VC). However, severing the petiole and applying high-pressure gas could affect air-seeding and the generated VC. We discuss potential artifacts arising from gas injection and recommend comparison of this method with a more standard procedure before it is assumed to be suitable for a given species.
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Affiliation(s)
- Uri Hochberg
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138
- ARO Volcani Center, Institute of Soil, Water and Environmental Sciences, Bet Dagan, 7505101 Israel
| | - Alexandre Ponomarenko
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Yong-Jiang Zhang
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138
- School of Biology and Ecology, University of Maine, Orono, Maine 04469
| | - Fulton E Rockwell
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138
| | - N Michele Holbrook
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138
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97
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Brodersen CR, Roddy AB, Wason JW, McElrone AJ. Functional Status of Xylem Through Time. ANNUAL REVIEW OF PLANT BIOLOGY 2019; 70:407-433. [PMID: 30822114 DOI: 10.1146/annurev-arplant-050718-100455] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Water transport in vascular plants represents a critical component of terrestrial water cycles and supplies the water needed for the exchange of CO2 in the atmosphere for photosynthesis. Yet, many fundamental principles of water transport are difficult to assess given the scale and location of plant xylem. Here we review the mechanistic principles that underpin long-distance water transport in vascular plants, with a focus on woody species. We also discuss the recent development of noninvasive tools to study the functional status of xylem networks in planta. Limitations of current methods to detect drought-induced xylem blockages (e.g., embolisms) and quantify corresponding declines in sap flow, and the coordination of hydraulic dysfunction with other physiological processes are assessed. Future avenues of research focused on cross-validation of plant hydraulics methods are discussed, as well as a proposed fundamental shift in the theory and methodology used to characterize and measure plant water use.
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Affiliation(s)
- Craig R Brodersen
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511, USA;
| | - Adam B Roddy
- School of Forestry and Environmental Studies, Yale University, New Haven, Connecticut 06511, USA;
| | - Jay W Wason
- School of Forest Resources, University of Maine, Orono, Maine 04469, USA
| | - Andrew J McElrone
- US Department of Agriculture, Agricultural Research Service, Davis, California 95616, USA
- Department of Viticulture and Enology, University of California, Davis, California 95616, USA
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98
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Abstract
Leaf water potential regulation is a key process in whole plant and ecosystem functioning. While low water potentials induced by open stomata may initially be associated with greater CO2 supply and a higher water flux from the rhizosphere to the canopy, they also inhibit cell growth, photosynthesis and ultimately water supply. Here, we show that plants regulate their leaf water potential in an optimal manner under given constraints using a simple leaf water status regulation model and data from a global dryland leaf water potential database. Model predictions agree strongly with observations across locations and species and are further supported by experimental data. Leaf water potentials non-linearly decline with soil water potential, underlining the shift from maximizing water supply to avoiding stress with declining water availability. Our results suggest that optimal regulation of the leaf water status under varying water supply and stress tolerance is a ubiquitous property of plants in drylands. The proposed model moreover provides a novel quantitative framework describing how plants respond to short- and long-term changes in water availability and may help elaborating models of plant and ecosystem functioning.
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99
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Villalobos-González L, Muñoz-Araya M, Franck N, Pastenes C. Controversies in Midday Water Potential Regulation and Stomatal Behavior Might Result From the Environment, Genotype, and/or Rootstock: Evidence From Carménère and Syrah Grapevine Varieties. FRONTIERS IN PLANT SCIENCE 2019; 10:1522. [PMID: 31850024 PMCID: PMC6900739 DOI: 10.3389/fpls.2019.01522] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 10/31/2019] [Indexed: 05/04/2023]
Abstract
Controversies exist regarding the iso/anisohydric continuum for classifying plant water-use strategies. Isohydricity has been argued to result from plant-environment interaction rather than it being an intrinsic property of the plant itself. Discrepancies remain regarding the degree of isohydricity (σ) of plants and their threshold for physiological responses and resistance to drought. Thus, the aim of this study was to evaluate the isohydricity of the grapevine varieties Syrah and Carménère under a non-lethal water deficit progression from veraison from two different locations, the Cachapoal Valley (CV) and Maipo Valley (MV), in central Chile and with different rootstock only in Syrah. For this purpose, the midday stem water potential (Ψmds) regulation and stomatal responses to drought, leaf traits related to pressure-volume curves, stomatal sensitivity to ABA, cavitation threshold, and photosynthetic responses were assessed. A higher atmospheric water demand was observed in the CV compared to the MV, with lower Ψmds values in the former for both varieties. Also, the σ values in Carménère were 1.11 ± 0.14 MPa MPa-1 and 0.68 ± 0.18 MPa MPa-1 in the CV and MV, respectively, and in Syrah they were 1.10 ± 0.07 MPa MPa-1 in the CV and 0.60 ± 0.10 MPa MPa-1 in the MV. Even though similar variations in σ between locations in both varieties were evident, Carménère plants showed a conserved stomatal response to Ψmds in both study sites, while those of Syrah resulted in a higher stomatal sensitivity to Ψmds in the site of lower σ. Besides the differences in seasonal weather conditions, it is likely that the different rootstock and clonal variability of each season in Syrah were able to induce coordinated changes in σ, Ψgs12, and osmotic potential at full turgor (π0). On the other hand, irrespective of the σ, and given the similarity between the π0 and Ψgs12 in leaves before drought, it seems that π0 could be a convenient tool for assessing the Ψmds threshold values posing a risk to the plants in order to aid the irrigation decision making in grapevines under controlled water deficit. Finally, water deficits in vineyards might irreversibly compromise the photosynthetic capacity of leaves.
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Affiliation(s)
- Luis Villalobos-González
- Facultad de Ciencias Agronómicas, Universidad de Chile, Santiago, Chile
- Programa de Doctorado en Ciencias Silvoagropecuarias y Veterinarias, Campus Sur Universidad de Chile, La Pintana, Chile
- *Correspondence: Luis Villalobos-González, ; Claudio Pastenes,
| | | | | | - Claudio Pastenes
- Facultad de Ciencias Agronómicas, Universidad de Chile, Santiago, Chile
- *Correspondence: Luis Villalobos-González, ; Claudio Pastenes,
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Levin AD, Williams LE, Matthews MA. A continuum of stomatal responses to water deficits among 17 wine grape cultivars (Vitis vinifera). FUNCTIONAL PLANT BIOLOGY : FPB 2019; 47:11-25. [PMID: 31615618 DOI: 10.1071/fp19073] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/19/2019] [Indexed: 06/10/2023]
Abstract
Vitis vinifera L. cultivars have been previously classified as isohydric, near-isohydric, anisohydric or isohydrodynamic, depending on the study. To test the hypothesis that V. vinifera cultivars' stomatal behaviour can be separated into distinct classes, 17 cultivars grown in a replicated field trial were subjected to three irrigation treatments to manipulate vine water status across multiple years. Predawn (ΨPD) and midday (Ψl) leaf water potential and midday stomatal conductance (gs) were measured regularly throughout several seasons. The relationship of gs to Ψl was best modelled as a sigmoidal function and maximum stomatal conductance (gmax), water status at the onset of stomatal closure (Ψl95), sensitivity of closure (gsensitivity) and water status at the end of closure (Ψl25) were compared. There were no significant differences in gmax among cultivars. Cultivar-specific responses of gs to Ψl were broadly distributed along a continuum based on the relationship between Ψl95 and gsensitivity. Season-long cultivar mean Ψl values were positively related to Ψl25. In general, cultivars responded similarly to one another at high and low water status, but their stomatal behaviour differed at moderate water deficits. The results show that V. vinifera cultivars possess both iso- and anisohydric stomatal behaviours that depend on the intensity of water deficits, and call into question previous classifications assuming a single behaviour.
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Affiliation(s)
- Alexander D Levin
- Department of Horticulture, Oregon State University, Corvallis, OR 97331, USA; and Southern Oregon Research and Extension Center, 569 Hanley Road., Central Point, OR 97502, USA; and Corresponding author.
| | - Larry E Williams
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA; and Kearney Agricultural Research and Extension Center, 9240 S. Riverbend Avenue., Parlier, CA 93648, USA
| | - Mark A Matthews
- Department of Viticulture and Enology, University of California, Davis, CA 95616, USA
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